Define your own namespace:
<Layout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:x="what.a.long.long.long.loooooong.packagename." > <x:MyView> </x:MyView> </Layout>
xmlns:x indicates that all tags starting with <x: should be viewed in the package that is defined in the namespace definition ( what.a.long.long.long.loooooong.packagename. in this case).
You can even use the namespace inside the tag itself:
<x:MyView xmlns:android="http://schemas.android.com/apk/res/android" xmlns:x="what.a.long.long.long.loooooong.packagename." />
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